Decision on existing triplex or turn into duplex to build SFH

[Bryant Blackwelder]

Hey so I just bought a triplex on an oversized lot and I have a situation where I can turn it back into a duplex and have just enough square footage to build a single family home any size on the empty space behind it or keep it a triplex!!!???!!

It’s built in 1910 I believe and was a duplex but someone made it into a triplex about 50 years ago and it’s on a 17,000 sq ft lot

I obviously need to figure out cost to build a new SFH. It's in the city limits here in Maryville TN. And there are a lot of businesses and people coming to the area.

Should I leave it or change it to be able to build later!?

I appreciate you guys and any advice I can get!!